Field of the Invention
The present invention is directed to devices adaptable to tractors or other vehicles for tracing on the ground the various lines of a path to be followed for spreading or spraying a treatment product or the like along parallel, relatively wide lanes, notably in agriculture.
In fact, treatments of this kind are applied nowdays by using spreading or spraying systems of relatively great length, for example from ten to twenty-six yards (9 to 24 meters). Therefore, the driver of a tractor equipped with this distributor must cover the corresponding ground area so that the treatment product be applied to parallel lanes having the width of the spreading or spraying ramp while avoiding both a double projection in certain areas and the absence of treatment at others. Consequently, the tractor driver must follow on the ground a series of strictly parallel lines spaced from each other by a distance equal to the width of the treatment lanes, and therefore to the length of the spreading or spraying ramp. However, due to the considerable width of these lanes, this result cannot be achieved without tracing beforehand the lines to be followed during the actual spreading or spraying operation.
Now, hitherto known methods and apparatus available for performing this preliminary tracing operation are not fully satisfactory.